| Project/Area Number |
11671514
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Anesthesiology/Resuscitation studies
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| Research Institution | University of the Ryukyus. |
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Principal Investigator |
TAKARA Itaru (2000) University of the Ryukyus, Department of Anesthesiology, assistant., 医学部, 助手 (60305208)
平良 豊 (1999) 琉球大学, 医学部・附属病院, 講師 (60144721)
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| Co-Investigator(Kenkyū-buntansha) |
SUGAHARA Kazuhiro University of the Ryukyus, Department of Anesthesiology, professor., 医学部, 教授 (20171126)
HIGA Yasutoshi University of the Ryukyus, Department of Anesthesiology, assistant., 医学部・附属病院, 助手 (00228701)
奥田 佳朗 琉球大学, 医学部, 教授 (10026883)
高良 到 琉球大学, 医学部・附属病院, 助手 (60305208)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2000: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1999: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Keywords | ADENOSINE / NMDA / GLUTAMATE / SPINAL CORD / RAT / HYPERALGESIA / アデノシンA2受容体 / 2-クロロアデノシン |
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| Research Abstract |
It has been reported that Adenosine A1 receptor activation induces antinociception in several traditional behavioral assays for antinociception including tail flick and hot plate tests in mice and rats, and inhibit the behavior induced by putative pain neurotransmitters. The purpose of this study is to examine the effects of adenosine A1 agonist on NMDA induced hyperalgesia and glutamate release in spinal cord induced by intrathecal NMDA infusion.
[Materials and Methods] Mail Sprague-Dawley rats were implanted with both chronic lumbar intrathecal twin catheter (PE-5) and microdialysis loop catheter under enflurane anesthesia. 3-5 days after surgery, NMDA was intrathecally infused by the flow rate of 180 pmol/min through the IT catheter followed by periodical assessment of paw thermal withdrawal latency. 10 min before or 30 min after the initiation of NMDA infusion, 2-chrolo adenosine was IT injected through the another IT catheter. During testing period, glutamate release in CSF was assessed by microdialysis method.
[Results] Continuous infusion of NMDA produced constant and long lasting thermal hyperalgesia. Both pre-treatment and post-treatment of 2-chroloadenosine inhibited the NMDA induced thermal hyperalgesia in a dose dependent manner and with a same potency. IT injection of 2-chroloadenosine significantly decreased CSF glutamate level even during NMDA continuous infusion.
[Conclusion] Adenosine A1 agonist represented the potent antinociceptive action on the centrally induced hyperalgesia model produced by NMDA IT infusion. Inhibition of glutamate release may be included in the mechanism by which activation of adenosine A1 receptor in the spinal cord produces the antinociception.
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